Is anyone familiar with this spec? It is the European spec for biodiesel. The ASTM spec for free and total glycerol is 0.240% (2,400 ppm). However, the EN14214 spec is 0.8% for monoglycerides, 0.2% for diglycerides, 0.2% for triglycerides, 0.02 for free glycerol, and then it says the total glycerol spec is 0.250%.
Can anyone explain why the total is less than the sum of mg, dg, and tg? Or why it is less than just the mg? Can anyone also explain why the mg spec (0.8%) is so forgiving?
Usually I see the monoglycerides are the last to break down, but usually the highest I see is 0.2-0.3%. If you were to have no dg, tg or free glycerol you could have 0.8% unreacted mg?
I would think the European standard would be more stringent than the American standard...
Doesn't make good sense to me. I even checked several different listings of the spec to see if there is a typo in there but every listing I found reads the same.
Maybe it's an either/or type thing.
If you don't have any luck here, you can check this UK biodiesel forum. http://www.vegetableoildiesel....umdisplay.php?fid=10
You may find more people familiar the EU standard there.
Thanks Double D do you have a link to the actual spec? I've googled it and found what I mentioned above.
I don't have a link to any official government document. Just what I found through a quick search using google.
yeah i searched google too and found about 5 links that had the spec i mentioned above.
i'm guessing you found the same thing?
Same thing that's listed on wiki.
If the spec is .8% mono's max then that would mean the glycerol for that contained would be around .2%
Using a SG of .88g/ml for bio.
92g/mol for glycerol.
282g/mol for oleic acid.
356g/mol for monoglyceride from the above.
25-26% of a mono is glycerol.
The max for Mono's is .8%
26% of .8%= .208% which is within the TG spec.
I ran some more numbers to figure out the sum of all the glycerides and glycerol.
Using a 900ml sample size.
Mono = 356g ... 25.8% is glycerol
Di = 620g ... 14.8% is glycerol
Tri = 884g ... 10.4% is glycerol
Glycerol = 92g ... 100% is glycerol
This is taking into account the missing H's and O of the combined glyceride.
The spec max
Monos = .8% of 900g = 7.2g x .258 = 1.86g glycerol
Di's = .2% of 900g = 1.8g x .148 = .266g glycerol
Tri's = .2% of 900g = 1.8g x .104 = .187g glycerol
Free = .02% of 900g = .18g x 1 = .18g glycerol
Total glycerol = 2.493g/900g sample size = .00277x100= .277% TG
Interesting. Thanks for the explanation, it makes a lot more sense.
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